A radar device for a vehicle is installed on the exterior of a vehicle and can detect or trace a distance, a speed, and an angle of a target device through radio wave transmission and reception.
Such a radar device for a vehicle includes internal electronic elements, such as an antenna configured to transmit or receive a radio wave and a radio frequency integrated circuit (RFIC) for a millimeter wave (mmWAVE), and a radome configured to protect the internal electronic elements. The radome functions to mechanically protect the internal electronic elements of the radar device for a vehicle from the external environment and minimize the loss of a radio wave transmitted to or received from the outside.
The radar device for a vehicle can be installed at the front or rear of a vehicle. A radar device for a vehicle installed at the front of a vehicle needs to have a remote detecting function and accordingly needs a high gain and a narrow beam width. Accordingly, the radome of the radar device for a vehicle installed at the front can have a planar shape having a uniform dielectric constant.
Meanwhile, since a radar device for a vehicle installed at the rear of a vehicle needs to detect areas in lateral and rearward directions of the vehicle which are not visible through side mirrors, the radar device for a vehicle needs a wide detection angle which is greater than or equal to a 130° field of view (FOV). To this end, there has been an attempt to use a wide angle antenna having a wide beam width, but there is a problem in that it is difficult to obtain a detection angle of a 130° FOV or more only with the wide angle antenna.